Handling FHIR Responses in InterSystems – Transforming to SDA

Question

Question

Ali Chaib · Feb 7

#API #Business Process (BPL) #FHIR #JSON #REST API #XML #Caché #Ensemble #HealthShare #InterSystems IRIS for Health

I understand that InterSystems provides functions to facilitate transactions between FHIR and HL7 via the SDA segment. My question is:

Does this transformation only work when InterSystems receives FHIR requests and converts them into HL7, or does it also support responses?
Specifically, if our operation sends a GET request to a broker and receives a FHIR response, does InterSystems support transforming this response into an SDA segment automatically?
Or should we manually parse and modify the response to handle it according to our needs?

What would be the best approach in this scenario? Any insights or best practices would be greatly appreciated!

Thanks in advance.

Product version: IRIS 2023.3

Discussion (3)1

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Ashok Kumar · Feb 10

Hello @Ali Chaib

FHIR to SDA

Yes we have built in transformation class available to FHIR ⇆ SDA and HS.FHIR.DTL.Util.API.Transform.FHIRToSDA3 is used to convert to SDA3 to FHIR
If you're goal to to convert to FHIR to SDA object then "HS.FHIR.DTL.Util.HC.SDA3.FHIR.Process" use this Business Process(BP) class to convert but this will send the request to BO again based on the BP configuration. Otherwise programmatically construct the input and pass the required values to the method in TransformStream class transformation class(which is in FHIR to SDA conversion business process) HS.FHIR.DTL.Util.API.Transform.SDA3ToFHIR for convert FHIR to SDA

SDA3 to HL7 conversion

There is no method for programmatically converting from SDA to HL7 v2.

from documentation. So, You need to read the JSON response, extract the required information, and transform it directly into an HL7 message

There are multiple DTL's available for SDA3 to HL7 v2 in package "HS.Gateway.SDA3.SDA3ToHL7." Can you check and utilize if it's helps

Thanks!

0 0

score 0 · Answer 1 · 2025-02-07T13:13:39-05:00

Hello @Ali Chaib

SDA, or Summary Document Architecture is an intermidary format. It's used to easily convert between multiple data formats--such as HL7 V2, C-CDA, C32, HL7 FHIR, and others.

I hope You are sending a GET request via HTTPOperation in FHIR interoperability production. You'll get the http response. There is no predefined transformation available to do it. You need to programmatically convert the response. I just convert the FHIR operation outcome to FHIR R4 outcome object directly.

ClassMethod fhirresponse()
{
	#;Assume the json as a fhir response
	Set fhiResponse = {"resourceType":"OperationOutcome","issue":[{"severity":"error","code":"not-found","diagnostics":"<HSFHIRErr>ResourceNotFound","details":{"text":"No resource with type 'Task' and id '33'"}}]}
	#dim opoutcome As HS.FHIRModel.R4.OperationOutcome = ##Class(HS.FHIRModel.R4.OperationOutcome).fromDao(fhiResponse)
	Write opoutcome.issue
}

score 0 · Answer 2 · 2025-02-10T09:04:57-05:00

Thank you @Ashok Kumar

Yes, I fully understand that SDA (Summary Document Architecture) is an intermediary format.
And yes, I am using the HTTP operation in my interoperability production.

When you say "You need to programmatically convert the response", do you mean:

Convert it into an object, or
Convert it into SDA?

If the goal is to convert it into an object, does that mean I should manually read the JSON entities/nodes, extract the relevant information, and transform it directly into an HL7 message—bypassing SDA entirely?

If the goal is to convert it into SDA, does that mean I must first transform the FHIR response into a FHIR request? If so, how? Because FHIR responses often contain additional fields that do not appear in FHIR requests, such as:

"type": "searchset",
"total": 1,
"search": {
    "mode": "match"
}

I’m asking these questions because, as you know, InterSystems provides built-in functionalities to automatically convert FHIR requests into SDA, such as:

Process: HS.FHIR.DTL.Util.HC.FHIR.SDA3.Process
Transform class: HS.FHIR.DTL.Util.API.Transform.FHIRToSDA3

These components accept FHIR requests and successfully transform them into SDA.

However, when handling FHIR responses, I tried extracting the payload, creating a new message, and sending it to HS.FHIR.DTL.Util.HC.FHIR.SDA3.Process. Unfortunately, the transformation failed—possibly because the FHIR response contains additional fields that the built-in functions don’t recognize.

It's worth noting that when I send a FHIR request to the exact same process, it transforms correctly into SDA (without these extra fields).